Installation to produce rapidly a heated fluid

ABSTRACT

In a multi-water-tube boiler installation a pair of horizontally arranged vertically spaced toroidal water reservoirs extend concentrically about a vertical axis. The reservoirs are interconnected by a plurality of generally vertically extending concentrically arranged rows of tubes and baffles are connected between adjacent rows of tubes so that heating gases directed downwardly from a centrally arranged burner flow first over the innermost row of tubes and then are guided for flow in the axial direction serially over the remaining rows of tubes. Annular rings are provided at least about the outer rows of tubes for directing a fluid over the tubes to remove soot. The burner, reservoirs, and tubes form a unitary assembly suspended from the roof of the boiler housing. The boiler housing is insulated and a feed water tank for supplying water to the reservoirs extends around the housing for recovering heat passing through the insulating material.

Tlite ttes tt arrault et all.

[54] TNSTALLATTUN T0 PRQDTMIE RAPTDLY A HEATED FLUID [72] Inventors: Rene Louis Barrault; Roland Edmond Weber, both of 39 avenue du petit Chambord, 92 Bourg la Reine, France [22] Filed: Apr. 28, 1970 [21] Appl. No.: 32,652

[30] Foreign Application Priority Data [4 Mar. 2%, W72

FOREIGN PATENTS OR APPLICATIONS 628,871 6/1963 Belgium ..122/338 470,418 12/1950 Canada ..l22/338 Primary Examineri(enneth W. Sprague Attorney-McGlew and Toren ABSTRACT In a multi-water-tube boiler installation a pair of horizontally arranged vertically spaced toroidal water reservoirs extend concentrically about a vertical axis. The reservoirs are interconnected by a plurality of generally vertically extending concentrically arranged rows of tubes and baffles are connected between adjacent rows of tubes so that heating gases directed downwardly from a centrally arranged burner flow first over the innermost row of tubes and then are guided for flow in the axial direction serially over the remaining rows of tubes. Annular rings are provided at least about the outer rows of tubes for directing a fluid over the tubes to remove soot. The burner, reservoirs, and tubes form a unitary assembly suspended from the roof of the boiler housing. The boiler housing is insulated and a feed water tank for supplying water to the reservoirs extends around the housing for recovering heat passing through the insulating material.

tqeieelllrex s {Flees PATENTEDMARZEB I972 3,651 790 Wm LOUIS. wmnm' "Mmwp E. WEELELR INSTALLATION T PRODUCE RAPIDLY A HEATED lFlLUllD This invention relates to an installation intended, as required, for producing hot water and/or hot steam at low or high pressure, by inexpensive compact means which operate very quickly.

This installation may be in various forms but in principle is of the multitubular water-tube boiler type and is characterized in that all its component parts and the relative flow paths of the various fluids are completely symmetrical with respect to a single longitudinal axis. This axis is vertical if it is required to utilise to the best advantage the natural flows produced by density differences, but it is also possible for it to be inclined to varying degrees, but without exceeding approximately 60 to the vertical.

More particularly, the installation according to the invention comprises a first toroidal water reservoir and a second toroidal water reservoir, the two reservoirs being disposed one above the other along a common vertical axis of symmetry and connected by vertical tubes distributed over a plurality of cylindrical zones concentric to the same axis, at the top of which a burner discharges hot gases vertically downwards.

Each toroidal reservoir has water supply and discharge tubes, the top toroidal reservoir also containing steam and/or water outlet tubes.

In order to produce a longer flow path for the gases, baffles in the form of annular sections are welded alternately to one toroidal reservoir and to the other between the cylindrical tube layers.

Finally, all the toroidal reservoir/water tube/baffle annular member components form a unitary assembly which is suspended from the roof of an insulating casing from which it can be readily extracted for repairs or maintenance.

The invention will be more readily understood from the following description of the accompanying drawing which is an exploded view of one embodiment of the installation according to the invention.

Referring to the drawing, the bottom toroidal reservoir 1 and the top toroidal reservoir 2 are concentric with a common axis of symmetry XY.

The two reservoirs are connected by rows of tubes, some of which are straight or curved, e.g. 3, while others are bent at two points in the same direction, e.g. 4, while others, e.g. 5, are bent so as to be connected to the reservoirs at a substantially normal angle, and then extend close to the other rows 3 and 4. The assembly formed by the rows 3, 4i, and 5 thus results in a compact generally cylindrical nest having the axis XY. This nest may also comprise a larger number of tube layers.

Baffles may be mounted between the rows in the form of annular sections extending from one reservoir to the other or, as shown at 6 and 7, one may extend from one reservoir to near the other, and vice versa, the said annular members each being inserted between two of the concentric rows of tubes.

A burner 8 applies a stream of heating gas F into the combustion chamber along the axis XY.

Sweeper tubes are shown at 9 and 10 and their function will be explained hereinafter.

An insulating panel 11 closes the combustion chamber beneath the reservoir 1.

The assembly forms a unit which is housed in an insulating jacket 12 and which can be introduced or removed completely at the top simply by removing the bolted plate 13 which closes the combustion chamber.

The operation of this installation in its simplest form as a boiler for a source of saturated steam is as follows:

The cold boiler feed water is introduced by any suitable means (not shown) into the top reservoir 2 until the latter is half full, as shown, where it mixes (assuming that the installation is operational) with unevaporated water which has started an operating cycle, as will be explained hereinafter, whereupon it descends to the lower reservoir 1 via the less heated tubes, i.e. the tubes 4, which are farthest away from the axis XY, and then the water from the reservoir ll heats up and rises via the tubes 3 and E to the reservoir 2 where it partially evaporates, the steam being collected at 14.

If, on the other hand, it is required to produce hot water, more particularly for supplying a heating installation, the following variant is used:

The cold feed water is introduced by any suitable means (not shown) into the bottom reservoir 1 and rises through the tubes 35 to the top reservoir 2, which is completely filled in this case, so that the water thus heated through the boiler escapes therefrom via the conduit M.

If required, a nest of tubes used as a heat exchanger can be disposed in the top reservoir 2 to make use of the heat of the water contained in this reservoir to heat a fluid flowing in the exchanger, such a fluid being at any pressure. The fluid may, for example, be service hot water.

In a variant, the straight tubes 3 may be replaced by two concentric annular members bounding a layer of water and formed with apertures for the radial flow of gases.

In a third embodiment of the invention, in order to produce saturated steam and hot water simultaneously, a similar additional reservoir (not shown) is disposed above the top reservoir 2 and communicates with the latter reservoir via members which provide for the flow of water between the completely filled reservoir 2 and the partially filled additional reservoir. Only the tubes 3 and 5 are required to lead into the reservoir 2 while the tubes 4 lead into the additional reservoir beneath the water so as to ensure that the feed water and already cycled water descend towards the reservoir ll.

A sweeping means is provided in all the above cases to eliminate soot carried by the gases and deposited on the tubes and battles, such means comprising a set of annular tubes 9-10 each supplying jets of fluid in a specific zone in order to expel such soot. The tubes 9-10 are fed by a suitable common source of steam or compressed air for example (not shown).

The gases originating from the burner 8 at F extend in the direction of the arrows F2, F3, F4 as far as the flue 115. Since the gases progressively cool along this path, when saturated steam is to be produced the water flows in the tubes 4 in the same direction as the gases which therefore heat it, while when hot water is produced the water flows in the tubes 3 in parallel current with and in the tubes 4 it flows in countercurrent with the gases which heat it.

The heat exchange therefore occurs in every case under favourable conditions.

This functional advantage and the advantages apparent from the foregoing description are completed by the following advantages as regards construction due to the concentricity of all the elements of the installation according to the invention.

First of all, taking any two points of the installation which are symmetrical with respect to the axis XY, such two points will both be situated either in the heating fluid or the heated fluid or in the metal so that their temperatures are equal and, depending upon circumstances, the heat flows resulting from the heat exchanges are equal, the directions and speeds of the fluids are equal and/or the mechanical stresses are equal.

Secondly, it is easy to suspend the heating surfaces from the detachable cover because the center of gravity is situated on the axis XY, thus allowing free expansion of the heating surfaces.

Thirdly, taking an existing apparatus it is an easy matter to extend the heating surfaces by adding additional heating surfaces and baffles concentrically around the existing ones, or by extending the existing ones. Similarly, their removal and exchange are easy and fast.

Fourthly, it is more convenient and economic to make toroidal reservoirs by the butt welding of commercially available bends than by the prior art methods using annular members and ends, which are thicker and more expensive.

The following may be mentioned as detail variants which still come within the scope of the invention:

Firstly, a feed tank 16 can be added to the installation, and be disposed concentrically around the insulation 12 so that the IAlnnn heat penetrating through the insulation can be recovered for heating the boiler feed water in the case of steam generation. The tank 16 continues at 17 in the form of a frame supporting the boiler, except in the zone 18 through which the gases flow.

Secondly, an additional tubular exchanger can be provided to superheat the saturated steam produced by the boiler.

Finally, although the above description refers solely to water, the boiler can also be used for heating other fluids, e.g. mineral or organic fluids.

We claim:

1. A multi-water-tube boiler installation having an upright axis for the fast production of a hot fluid, comprises a first toroidal water reservoir extending concentrically about the upright axis, a second toroidal water reservoir extending concentrically about the upright axis and spaced upwardly from said first toroidal water reservoir, a plurality of concentrically arranged rows of upwardly extending tubes connected at their lower ends to said first toroidal water reservoir and at their upper ends to said second toroidal water reservoir, a burner located on the upright axis for directing hot gases downwardly within the innermost concentrically arranged row of tubes, means for guiding the flow of hot gases from said burner in the axial direction serially over said rows of tubes passing first over the innermost row and then in turn over each next outwardly located row of tubes, and means for directing a flow of fluid over at least the outwardly disposed rows of tubes and over said means for guiding the flow of hot gases for expelling soot from the surfaces of said tubes and said guide means.

2. A multi-water-tube boiler installation, as set forth in claim 6, wherein said means for guiding the flow of hot gases comprises a plurality of annularly shaped upwardly extending concentrically arranged baffles, the one of said baffles located closest to the upright axis being welded at its upper end to said second toroidal water reservoir and at its lower end being spaced upwardly from said first toroidal water reservoir, and the next outer said baffle being welded at its lower end to said first toroidal water reservoir and being spaced at its upper end below said second toroidal water reservoir, a housing laterally enclosing said rows of tubes and forming a combustion chamber containing said rows of tubes, and a plate secured to said first toroidal reservoir for forming a closure for the lower end of the flow gas path directed downwardly from said burner.

3. A multi-water-tube boiler installation, as set forth in claim 1, wherein a housing laterally encloses said rows of tubes, a top plate secured to said housing and forming a roof for said boiler, said first and second toroidal reservoirs, said rows of tubes and said baffles forming a unitary assembly secured to and extending downwardly from said plate so that the unitary assembly can be readily extracted for repairs and maintenance.

4. A multi-water-tube boiler, as set forth in claim 3, wherein insulation is positioned on the surface of said housing laterally enclosing said tubes, a concentrically arranged feed tank enclosing at least a portion of said housing for recovering heat penetrating through the insulating material and using the heat recovered in said tank for preheating the liquid introduced into said reservoirs.

""070 men 

1. A multi-water-tube boiler installation having an upright axis for the fast production of a hot fluid, comprises a first toroidal water reservoir extending concentrically about the upright axis, a second toroidal water reservoir extending concentrically about the upright axis and spaced upwardly from said first toroidal water reservoir, a plurality of concentrically arranged rows of upwardly extending tubes connected at their lower ends to said first toroidal water reservoir and at their upper ends to said second toroidal water reservoir, a burner located on the upright axis for directing hot gases downwardly within the innermost concentrically arranged row of tubes, means for guiding the flow of hot gases from said burner in the axial direction serially over said rows of tubes passing first over the innermost row and then in turn over each next outwardly located row of tubes, and means for directing a flow of fluid over at least the outwardly disposed rows of tubes and over said means for guiding the flow of hot gases for expelling soot from the surfaces of said tubes and said guide means.
 2. A multi-water-tube boiler installation, as set forth in claim 6, wherein said means for guiding the flow of hot gases comprises a plurality of annularly shaped upwardly extending concentrically arranged baffles, the one of said baffles located closest to the upright axis being welded at its upper end to said second toroidal water reservoir and at its lower end being spaced upwardly from said first toroidal water reservoir, and the next outer said baffle being welded at its lower end to said first toroidal water reservoir and being spaced at its upper end below said second toroidal water reservoir, a housing laterally enclosing said rows of tubes and forming a combustion chamber containing said rowS of tubes, and a plate secured to said first toroidal reservoir for forming a closure for the lower end of the flow gas path directed downwardly from said burner.
 3. A multi-water-tube boiler installation, as set forth in claim 1, wherein a housing laterally encloses said rows of tubes, a top plate secured to said housing and forming a roof for said boiler, said first and second toroidal reservoirs, said rows of tubes and said baffles forming a unitary assembly secured to and extending downwardly from said plate so that the unitary assembly can be readily extracted for repairs and maintenance.
 4. A multi-water-tube boiler, as set forth in claim 3, wherein insulation is positioned on the surface of said housing laterally enclosing said tubes, a concentrically arranged feed tank enclosing at least a portion of said housing for recovering heat penetrating through the insulating material and using the heat recovered in said tank for preheating the liquid introduced into said reservoirs. 